The time went by really slowly, but finally the moment arrived and they were ready to open the hatch. Mike and Misha called me closer and told me to take a good whiff because this would be the first time I would smell “SPACE.”

They said it is a very unique smell. As they pulled the hatch open on the Soyuz side, I smelled “SPACE.” It was strange… kind of like burned almond cookie. I said to them, “It smells like cooking” and they both looked at me like I was crazy and exclaimed:”Cooking!”

I said, “Yes… sort of like something is burning… I don’t know it is hard to explain…”

She’s not the first to describe the smell of space this way, as something burned. When Terry Gross of Fresh Airinterviewed astronaut Jerry Linenger in 2001, she asked him what outer space smelled like. Here’s his response:

Flying into Mir, it smells sort of like dirty sweat socks in a guys’ locker room. Actual smell of space, though, that’s a very interesting question. When we would open a hatch, for example, that was exposed to the vacuum of space, uh, there’s always a double hatch, and so you open the one hatch, you now have the pure smell of space. And it’s a uh, tough — you know, any aroma is tough to describe, but it has a distinct smell, and it’s sort of a burned-out, uh, after-the-fire, the next-morning-in-your-fireplace sort of smell. And that’s the real smell of the vacuum of space.

NOTE 10/30/06: John Baez’ comment below made me ask myself if this burned-out smell is the smell of “the vacuum of space” or the smell of the spacearound Mir– the scent of a space program rather than the real “smell of space.”

Gasses and vapors vented from the space station would continue in orbit around the earth with the station.
And then there’s the propellent, exhaust and outgassing of everything we’ve sent up into orbit for the last 50 years. A lot of that stuff would still be orbiting. So maybe what they are smelling is the smell of low earth orbit. It would be interesting to test the smell of interplanetary space some day.